182._duplicate_emails.md

182. duplicate-emails 查找重复的电子邮箱

难度: Easy

刷题内容

原题连接

• https://leetcode.com/problems/duplicate-emails
• https://leetcode-cn.com/problems/duplicate-emails

内容描述

编写一个 SQL 查询，查找 Person 表中所有重复的电子邮箱。

示例：
+----+---------+
| Id | Email   |
+----+---------+
| 1  | [email protected] |
| 2  | [email protected] |
| 3  | [email protected] |
+----+---------+

根据以上输入，你的查询应返回以下结果：
+---------+
| Email   |
+---------+
| [email protected] |
+---------+

说明：所有电子邮箱都是小写字母。

解题方案

思路 1

select Email
from Person
group by Email
having count(1)>1

或者

select Email from Person group by Email having count(Email) > 1